In PCI DSS, what is meant by "network segmentation"?

Network segmentation refers to the practice of dividing a larger network into smaller, isolated segments or zones, which enhances security by controlling traffic flow and limiting access to sensitive data. This separation allows organizations to implement tailored security measures for each segment, minimizing the risk of a breach in one area affecting the entire network. By isolating the cardholder data environment (CDE) from other parts of the network, an organization can apply stricter security controls and monitor traffic more effectively, which is a key requirement of PCI DSS to protect cardholder information.

The other options do not accurately describe network segmentation. Increasing bandwidth does not relate to the segmentation of a network; instead, it focuses on the speed and capacity of data transfer. Combining multiple networks could potentially increase vulnerability instead of improving security. Finally, while cloud services can be part of an organization's infrastructure, utilizing them is not inherently linked to the concept of network segmentation as defined by PCI DSS.